The invention relates to the suspension of a vehicle for rugged terrain with a wheel or wheel-like ground engaging element, the ground-engaging surface of which has the shape of a body of revolution and which is journalled on a primary axle, the primary axle being freely rotatable around a secondary axle which is connected with the frame of the vehicle.
Different travel gears with track chains or wheels, sometimes with their combinations, have been used with actually known vehicles for rugged terrain in order to improve their riding characteristics. These travel gears, however, meet requirements from the point of view of the possibility of passage over rugged terrain to a limited degree only, and their manufacturing costs are relatively high. Travel gears comprising cylindrical bodies with axes parallel with the longitudinal axis of the vehicle and provided on their peripheries with a helix do not allow the vehicle to achieve higher speeds on even ground. In other travel gears provided with so-called walking mechanisms, problems arise with the control and with the stability of the vehicles.
Known small vehicles, for instance power driven minicars for invalids, or man powered vehicles such as wheel chairs, used for overcoming rugged terrain, particularly steps and similar obstacles, employ in addition to a common travel gear another gear acting solely when rugged terrain has to be overcome. Such other gear includes extensible supports, tiltable shafts with helices, and the like. Their disadvantage, in addition to the complicated design of these additional gears, is the requirement of an additional control device, the operation of which is an encumbrance for those manning such a vehicle.